First of all, I would like to say that I like the revamped Grim Ward skill, it is now useful but still clunky. 
With the recent buffs to the skill :
- Causes nearby monsters to flee
- Grim Ward slows down enemies by 11%, up to 63% (lvl 20 Grim Ward)
- Increases damage taken by affected monsters by 25%, up to 120% (lvl 20 Find Potion)
- Area of effect of 4 yards, up to 16.6 yards (lvl 20 Grim Ward)
Synergy :
At first I found it annoying to have a synergy for the damage buff on Find Potion, since it requires an investment of 40 skill points to have the full potential.
Then seeing that Find Item also received a synergy from Find Potion, I think that the investment is still paying off.
Casting on corpses :
Having to cast Grim Ward on a corpse is a big disadvantage to the skill, since it forces the player to first target a monster.
Once the monster is killed, the player must get very close to the body in order to cast the skill, and then all the remaining monsters runs in all opposite directions.
I noticed several things :
1- The fear curse is continuously applied to all monsters within the radius of the Grim Ward. However, it is not the position of the Grim Ward that the monsters flee, but rather the positioning of the Barbarian. ***(Bug or intent?)
2- Certain types of monsters do not offer the possibility of using their corpse to create a Grim Ward.
Exemple (Every skeleton monster types, but also Souls, Wraith, Oblivion Knight, Swarm, Thorned Hulk and probably more. ***(Bug or intent?)
…Find Potion seems to follow the same rule.
Suggestions :
1- Remove corpse restriction and allow the skill to be cast anywhere
or… Allow the skill to be cast from a longer range + Allow any monster corpse to create a Grim Ward (Just like Find Item works)
2- Modify the fear curse to actually make the monster flee from the Grim Ward.
or… simply remove the curse.